Backports release 1.11

NEWS.md

@@ -87,7 +87,6 @@ New library functions
 * `Sys.username()` can be used to return the current user's username ([#51897]).
 * `Sys.isreadable(), Sys.iswritable()` can be used to check if the current user has access permissions
   that permit reading and writing, respectively. ([#53320]).
-* `wrap(Array, m::Union{MemoryRef{T}, Memory{T}}, dims)` is the safe counterpart to `unsafe_wrap` ([#52049]).
 * `GC.logging_enabled()` can be used to test whether GC logging has been enabled via `GC.enable_logging` ([#51647]).
 * `IdSet` is now exported from Base and considered public ([#53262]).
 * `@time` now reports a count of any lock conflicts where a `ReentrantLock` had to wait, plus a new macro

base/abstractarray.jl

@@ -1473,7 +1473,20 @@ function _setindex!(::IndexCartesian, A::AbstractArray, v, I::Vararg{Int,M}) whe
     r
 end
 
-_unsetindex!(A::AbstractArray, i::Integer) = _unsetindex!(A, to_index(i))
+function _unsetindex!(A::AbstractArray, i::Integer...)
+    @_propagate_inbounds_meta
+    _unsetindex!(A, map(to_index, i)...)
+end
+
+function _unsetindex!(A::AbstractArray{T}, i::Int...) where T
+    # this provides a fallback method which is a no-op if the element is already unassigned
+    # such that copying into an uninitialized object generally always will work,
+    # even if the specific custom array type has not implemented `_unsetindex!`
+    @inline
+    @boundscheck checkbounds(A, i...)
+    allocatedinline(T) || @inbounds(!isassigned(A, i...)) || throw(MethodError(_unsetindex!, (A, i...)))
+    return A
+end
 
 """
     parent(A)

base/array.jl

@@ -219,7 +219,12 @@ function _unsetindex!(A::Array, i::Int)
     @inbounds _unsetindex!(GenericMemoryRef(A.ref, i))
     return A
 end
-
+function _unsetindex!(A::Array, i::Int...)
+    @inline
+    @boundscheck checkbounds(A, i...)
+    @inbounds _unsetindex!(A, _to_linear_index(A, i...))
+    return A
+end
 
 # TODO: deprecate this (aligned_sizeof and/or elsize and/or sizeof(Some{T}) are more correct)
 elsize(::Type{A}) where {T,A<:Array{T}} = aligned_sizeof(T)
@@ -3062,54 +3067,3 @@ intersect(r::AbstractRange, v::AbstractVector) = intersect(v, r)
         _getindex(v, i)
     end
 end
-
-"""
-    wrap(Array, m::Union{Memory{T}, MemoryRef{T}}, dims)
-
-Create an array of size `dims` using `m` as the underlying memory. This can be thought of as a safe version
-of [`unsafe_wrap`](@ref) utilizing `Memory` or `MemoryRef` instead of raw pointers.
-"""
-function wrap end
-
-# validity checking for _wrap calls, separate from allocation of Array so that it can be more likely to inline into the caller
-function _wrap(ref::MemoryRef{T}, dims::NTuple{N, Int}) where {T, N}
-    mem = ref.mem
-    mem_len = length(mem) + 1 - memoryrefoffset(ref)
-    len = Core.checked_dims(dims...)
-    @boundscheck mem_len >= len || invalid_wrap_err(mem_len, dims, len)
-    if N != 1 && !(ref === GenericMemoryRef(mem) && len === mem_len)
-        mem = ccall(:jl_genericmemory_slice, Memory{T}, (Any, Ptr{Cvoid}, Int), mem, ref.ptr_or_offset, len)
-        ref = MemoryRef(mem)
-    end
-    return ref
-end
-
-@noinline invalid_wrap_err(len, dims, proddims) = throw(DimensionMismatch(
-    "Attempted to wrap a MemoryRef of length $len with an Array of size dims=$dims, which is invalid because prod(dims) = $proddims > $len, so that the array would have more elements than the underlying memory can store."))
-
-@eval @propagate_inbounds function wrap(::Type{Array}, m::MemoryRef{T}, dims::NTuple{N, Integer}) where {T, N}
-    dims = convert(Dims, dims)
-    ref = _wrap(m, dims)
-    $(Expr(:new, :(Array{T, N}), :ref, :dims))
-end
-
-@eval @propagate_inbounds function wrap(::Type{Array}, m::Memory{T}, dims::NTuple{N, Integer}) where {T, N}
-    dims = convert(Dims, dims)
-    ref = _wrap(MemoryRef(m), dims)
-    $(Expr(:new, :(Array{T, N}), :ref, :dims))
-end
-@eval @propagate_inbounds function wrap(::Type{Array}, m::MemoryRef{T}, l::Integer) where {T}
-    dims = (Int(l),)
-    ref = _wrap(m, dims)
-    $(Expr(:new, :(Array{T, 1}), :ref, :dims))
-end
-@eval @propagate_inbounds function wrap(::Type{Array}, m::Memory{T}, l::Integer) where {T}
-    dims = (Int(l),)
-    ref = _wrap(MemoryRef(m), (l,))
-    $(Expr(:new, :(Array{T, 1}), :ref, :dims))
-end
-@eval @propagate_inbounds function wrap(::Type{Array}, m::Memory{T}) where {T}
-    ref = MemoryRef(m)
-    dims = (length(m),)
-    $(Expr(:new, :(Array{T, 1}), :ref, :dims))
-end

base/broadcast.jl

@@ -517,8 +517,8 @@ function _bcs(shape::Tuple, newshape::Tuple)
     return (_bcs1(shape[1], newshape[1]), _bcs(tail(shape), tail(newshape))...)
 end
 # _bcs1 handles the logic for a single dimension
-_bcs1(a::Integer, b::Integer) = a == 1 ? b : (b == 1 ? a : (a == b ? a : throw(DimensionMismatch("arrays could not be broadcast to a common size; got a dimension with lengths $a and $b"))))
-_bcs1(a::Integer, b) = a == 1 ? b : (first(b) == 1 && last(b) == a ? b : throw(DimensionMismatch("arrays could not be broadcast to a common size; got a dimension with lengths $a and $(length(b))")))
+_bcs1(a::Integer, b::Integer) = a == 1 ? b : (b == 1 ? a : (a == b ? a : throw(DimensionMismatch(LazyString("arrays could not be broadcast to a common size; got a dimension with lengths ", a, " and ", b)))))
+_bcs1(a::Integer, b) = a == 1 ? b : (first(b) == 1 && last(b) == a ? b : throw(DimensionMismatch(LazyString("arrays could not be broadcast to a common size; got a dimension with lengths ", a, " and ", length(b)))))
 _bcs1(a, b::Integer) = _bcs1(b, a)
 _bcs1(a, b) = _bcsm(b, a) ? axistype(b, a) : _bcsm(a, b) ? axistype(a, b) : throw(DimensionMismatch(LazyString("arrays could not be broadcast to a common size: a has axes ", a, " and b has axes ", b)))
 # _bcsm tests whether the second index is consistent with the first
@@ -1057,7 +1057,7 @@ end
 
 
 @noinline throwdm(axdest, axsrc) =
-    throw(DimensionMismatch("destination axes $axdest are not compatible with source axes $axsrc"))
+    throw(DimensionMismatch(LazyString("destination axes ", axdest, " are not compatible with source axes ", axsrc)))
 
 function restart_copyto_nonleaf!(newdest, dest, bc, val, I, iter, state, count)
     # Function barrier that makes the copying to newdest type stable

base/exports.jl

@@ -460,7 +460,6 @@ export
     vcat,
     vec,
     view,
-    wrap,
     zeros,
 
 # search, find, match and related functions

base/genericmemory.jl

@@ -288,3 +288,27 @@ function indcopy(sz::Dims, I::GenericMemory)
     src = eltype(I)[I[i][_findin(I[i], i < n ? (1:sz[i]) : (1:s))] for i = 1:n]
     dst, src
 end
+
+# Wrapping a memory region in an Array
+@eval begin # @eval for the Array construction. Block for the docstring.
+    function reshape(m::GenericMemory{M, T}, dims::Vararg{Int, N}) where {M, T, N}
+        len = Core.checked_dims(dims...)
+        length(m) == len || throw(DimensionMismatch("parent has $(length(m)) elements, which is incompatible with size $(dims)"))
+        ref = MemoryRef(m)
+        $(Expr(:new, :(Array{T, N}), :ref, :dims))
+    end
+
+    """
+        view(m::GenericMemory{M, T}, inds::Union{UnitRange, OneTo})
+
+    Create a vector `v::Vector{T}` backed by the specified indices of `m`. It is only safe to
+    resize `v` if `m` is subseqently not used.
+    """
+    function view(m::GenericMemory{M, T}, inds::Union{UnitRange, OneTo}) where {M, T}
+        isempty(inds) && return T[] # needed to allow view(Memory{T}(undef, 0), 2:1)
+        @boundscheck checkbounds(m, inds)
+        ref = MemoryRef(m, first(inds)) # @inbounds would be safe here but does not help performance.
+        dims = (Int(length(inds)),)
+        $(Expr(:new, :(Array{T, 1}), :ref, :dims))
+    end
+end

base/gmp.jl

@@ -754,7 +754,7 @@ function string(n::BigInt; base::Integer = 10, pad::Integer = 1)
     iszero(n) && pad < 1 && return ""
     nd1 = ndigits(n, base=base)
     nd  = max(nd1, pad)
-    sv  = Base.StringVector(nd + isneg(n))
+    sv  = Base.StringMemory(nd + isneg(n))
     GC.@preserve sv MPZ.get_str!(pointer(sv) + nd - nd1, base, n)
     @inbounds for i = (1:nd-nd1) .+ isneg(n)
         sv[i] = '0' % UInt8

base/intfuncs.jl

@@ -742,7 +742,7 @@ ndigits(x::Integer; base::Integer=10, pad::Integer=1) = max(pad, ndigits0z(x, ba
 function bin(x::Unsigned, pad::Int, neg::Bool)
     m = top_set_bit(x)
     n = neg + max(pad, m)
-    a = StringVector(n)
+    a = StringMemory(n)
     # for i in 0x0:UInt(n-1) # automatic vectorization produces redundant codes
     #     @inbounds a[n - i] = 0x30 + (((x >> i) % UInt8)::UInt8 & 0x1)
     # end
@@ -769,7 +769,7 @@ end
 function oct(x::Unsigned, pad::Int, neg::Bool)
     m = div(top_set_bit(x) + 2, 3)
     n = neg + max(pad, m)
-    a = StringVector(n)
+    a = StringMemory(n)
     i = n
     while i > neg
         @inbounds a[i] = 0x30 + ((x % UInt8)::UInt8 & 0x7)
@@ -844,7 +844,7 @@ end
 
 function dec(x::Unsigned, pad::Int, neg::Bool)
     n = neg + ndigits(x, pad=pad)
-    a = StringVector(n)
+    a = StringMemory(n)
     append_c_digits_fast(n, x, a, 1)
     neg && (@inbounds a[1] = 0x2d) # UInt8('-')
     String(a)
@@ -853,7 +853,7 @@ end
 function hex(x::Unsigned, pad::Int, neg::Bool)
     m = 2 * sizeof(x) - (leading_zeros(x) >> 2)
     n = neg + max(pad, m)
-    a = StringVector(n)
+    a = StringMemory(n)
     i = n
     while i >= 2
         b = (x % UInt8)::UInt8
@@ -880,7 +880,7 @@ function _base(base::Integer, x::Integer, pad::Int, neg::Bool)
     b = (base % Int)::Int
     digits = abs(b) <= 36 ? base36digits : base62digits
     n = neg + ndigits(x, base=b, pad=pad)
-    a = StringVector(n)
+    a = StringMemory(n)
     i = n
     @inbounds while i > neg
         if b > 0
@@ -956,7 +956,7 @@ julia> bitstring(2.2)
 function bitstring(x::T) where {T}
     isprimitivetype(T) || throw(ArgumentError("$T not a primitive type"))
     sz = sizeof(T) * 8
-    str = StringVector(sz)
+    str = StringMemory(sz)
     i = sz
     @inbounds while i >= 4
         b = UInt32(sizeof(T) == 1 ? bitcast(UInt8, x) : trunc_int(UInt8, x))

base/iobuffer.jl

@@ -42,7 +42,7 @@ end
 
 # allocate Vector{UInt8}s for IOBuffer storage that can efficiently become Strings
 StringMemory(n::Integer) = unsafe_wrap(Memory{UInt8}, _string_n(n))
-StringVector(n::Integer) = wrap(Array, StringMemory(n))
+StringVector(n::Integer) = view(StringMemory(n), 1:n)::Vector{UInt8}
 
 # IOBuffers behave like Files. They are typically readable and writable. They are seekable. (They can be appendable).
 
@@ -456,7 +456,7 @@ function take!(io::IOBuffer)
         if nbytes == 0 || io.reinit
             data = StringVector(0)
         elseif io.writable
-            data = wrap(Array, MemoryRef(io.data, io.offset + 1), nbytes)
+            data = view(io.data, io.offset+1:nbytes+io.offset)
         else
             data = copyto!(StringVector(io.size), 1, io.data, io.offset + 1, nbytes)
         end
@@ -465,7 +465,7 @@ function take!(io::IOBuffer)
         if nbytes == 0
             data = StringVector(0)
         elseif io.writable
-            data = wrap(Array, MemoryRef(io.data, io.ptr), nbytes)
+            data = view(io.data, io.ptr:io.ptr+nbytes-1)
         else
             data = read!(io, data)
         end
@@ -491,11 +491,7 @@ state.  This should only be used internally for performance-critical
 It might save an allocation compared to `take!` (if the compiler elides the
 Array allocation), as well as omits some checks.
 """
-_unsafe_take!(io::IOBuffer) =
-    wrap(Array, io.size == io.offset ?
-        MemoryRef(Memory{UInt8}()) :
-        MemoryRef(io.data, io.offset + 1),
-        io.size - io.offset)
+_unsafe_take!(io::IOBuffer) = view(io.data, io.offset+1:io.size)
 
 function write(to::IO, from::GenericIOBuffer)
     written::Int = bytesavailable(from)